The ZSW designed, developed and built the test site together with the University of Stuttgart, the University of Tübingen, the Technical University of Munich, the Karlsruhe Institute of Technology, and with Aalen University and Esslingen University from the WindForS wind energy research cluster in southern Germany. The wind test site was inaugurated by Minister-President of Baden-Württemberg Winfried Kretschmann together with Environment Minister Thekla Walker and Minister for Regional Development and Housing Nicole Razavi. The representatives of the Jülich project funding body, the district authority and local councils were also in attendance. “Baden-Württemberg remains a place with a great future in the wind energy sector. The new WINSENT test site is the first research facility of its kind in mountainous terrain – anywhere in the world. Statistics to date show that only one in five wind turbines is located in mountainous terrain. We need significantly more for an effective ramp-up. There is a need for acceptance and good framework conditions, accompanied by the demand for new technical solutions,” said Minister-President Winfried Kretschmann, “and the test site is furthering this cause.” Most wind turbines in the world are currently located in relatively flat terrain, primarily on coastal plains. Significantly greater exploitation of all the existing wind energy potential will be required to meet the ambitious climate targets, however, therefore more wind power will have to be generated now and in the future, including in mountainous terrain. These specific conditions call for efficient site development and reliable operation of wind turbines, giving rise to a need for optimisation in many respects, such as in site evaluation, yield assessments, and in the technical service life of system components. The research work on the test site is intended to close these gaps so as to enable economical operation of wind turbines in mountainous terrain and thereby promote global climate control.
Development and testing of new technologies
The wind energy test site is located on the edge of the Stöttener Berg mountain on the border between the towns of Donzdorf and Geislingen an der Steige on a forest clearing above the Albtrauf escarpment. The wind speed is sufficiently high for the research project and is characterised by high levels of turbulence and changing oblique currents. “The site is a perfect match for our research, and our work is also attracting great interest internationally,” said project manager Andreas Rettenmeier. “The conditions are typical for wind energy sites in complex mountainous terrain and are therefore ideal for developing and testing new technologies but also for exploring ways of encouraging environmentally-friendly moves in the expansion of wind energy,” he added. The research on the test site may focus on the specific characteristics of wind energy use in complex mountainous terrain but the results obtained from wind site modelling, the knowledge about more robust turbine designs, and the insights into efficient control, greater protection for systems and optimised economic management can be adapted for all wind energy locations, both onshore and offshore. They will therefore also serve to enhance and develop the use of wind energy as a whole.
Establishing an unrivalled data pool
here are four meteorological measuring masts at the site reaching a height of 100 metres, arranged in two pairs in front of and behind the two research wind turbines. They record the speed and direction of the wind, air temperature, humidity and air pressure at different altitudes. Optical laser systems also measure the turbine starting and wake flows. The two wind turbines are identical in construction and each have an installed capacity of 750 kilowatts. The rotor diameter is 54 metres and the total height is almost 100 metres. They are comparatively small, but ideal for research assignments because of the relative ease of reconstruction in order to test individual elements while still allowing the results to be scaled up to large modern systems thanks to digital twins (numerical computer models). The turbines are fitted with ample measuring sensors from the foundations all the way to the rotor blades. The test site is primarily made unique by the unrestricted access to the system design data and the control of the wind turbines. When conducting experiments and tests, the research scientists fit oneof the two wind turbines with the new developments at any given time, leaving the second one unchanged to serve as a reference and thereby allowing evidence of the effectiveness of innovations to be shown through direct comparison. This approach enables a wealth of completely new insights and findings. The aim in further steps is to work with industry to transfer the research results to large-scale commercial systems. The test site therefore offers companies and research institutions unprecedented opportunities at regional, national and international level for the development, testing and validation of system components, parts and control algorithms, and it also provides a variety of data for a wide and diverse range of applications – from meteorology and flow ratios right through to mechanical stress on assemblies.
Transfer of know-how to industry and society
Due to its special location, the wind energy test site will also enable extensive research into nature conservation alongside its purely technical research remit. It will seek to prevent conflicts between wildlife protection and climate action and, in so doing, to address a key point of criticism in relation to the use of wind energy. The research test site will open up a number of other avenues for the exploitation of the potential for innovation in relation to wind energy, from turbine design, turbine operation and optimised maintenance aided by artificial intelligence (AI) right through to the recycling of glass-fibre reinforced plastics (GRP) of the type built into rotor blades. The operation of the test site and the associated research work are clearly aimed at tapping into this potential for the global market, preferably with companies from Baden-Württemberg. Funding of around 13 million euro has been provided for the build by the Federal Ministry for Economic Affairs and Climate Action (BMWK) and by the Baden-Württemberg Ministry of the Environment, Climate Protection and the Energy Sector.